Stabilization of a zein solution by clarification



Nov. 12, 1940. L. c. SWALLEN STABILIZATION OF A ZEIN SOLUTION BY CLARIFICATION Filed Jan. 13, 1940 extract is not intended to, nor does it to any or a solution made by dissolving dried zein in soluble zein in such solution. Zein solutions conabout the separation oi. the extract into two liqg zein. and upon the concentration of the solution, or slightly higher. Therefore the cooling should 1' the solution will change to a gelwill be very con- 20 0. (68' I"), but the solution cooled to this Patented Nov. 12, 1940 I i UNITED- STATES PATENT 'orrics Lloyd 0. Swallen, Ann. 111., calm: to Corn Prodnets Refining Company, New York, N. Y, a cor poration of New Jersey Application January 13, 1940, Serial No. 313,671

9 Claims. (Cl. 134-12) This, invention relates to the production of protein component of maize is to use as a solzein; and the object oi the invention is to provent ethyl alcohol 92%-93% concentration by vide atreatment of the zein in alcoholic soluvolume, which concentrationmay bevaried betion whereby the stability of the solution will-be I tween 88% or lower and 95%, and to carry on substantially increased; that is to say, whereby the extraction in a rotating drum with an agitathe tendencyoi the zein in solution to become tor at a temperature of 60 C. for one and a half denatured, that is, insoluble, will be to a large to two hours. A suitable amount of alkali, say extent counter-acted, permitting the solution to 0.9% sodium hydroxide based on the weight of I be kept in a useable state for a much more pro-- the gluten meal may be added to the material in I i longed period of time than has heretofore been the drum. The extracted zein will be in the 10 possible. I neighborhood of 4.5-6.5 grams to 100 cubic cen- The invention is based upon the discovery that timeters of the solvent. The meal is then centhe known tendency for zein in solution to betriiuged and washed with alcohol, giving a zein come gradually insoluble in character, so that a concentration in the extract of 6 grams per 100 5 solution of zein it left to stand will become a gel cubic centimeters, which may vary between 4 in a relatively briei time, is due to the presence and 6 grams, dependent upon the strength of the in the solution of insoluble bodies such as denaalcohol, the character oi the gluten and the protured zein, or other protein substances, which act, po iq of alco l to lut n a probably catalytically, to insolubilize the soluble The extraction may be carried out also with u zein. These insoluble substances are present or isopropyl alcohol, instead of ethyl alcohol, of from .20 develop to some extent in all extracts produced 82% to 87% concentration, at a temperature of by present methods, and are not removed, or at 60' 0. (140 F.) for 1.5 to 2 hours. The extract least completely removed, by the ordinary methwill contain per 100 cubic centimeters about 6 ads of clarification by filtering now used, which rams of wi h h P s is disclosed in u methods are intended, as a matter oi tact, merely pending application of the a licant, filed Noas to se te from the solution particles or gluten vember 14, 1938, Serial No. 21, ,307. meal ed over from the extracting'apparatus. A zein extract obtained by either of the. above The ordinary expedient, that is. of filtering the methods, or by any other method of extraction, 1

go considerable exten remove the insoluble zein aqueous alcohol or other solvent, is subjected, in so bodies, or. other pro in substances which, as apaccordance with the present invention, to a rapid v plicant has discovered, bring about the insolubilooolingoperation for the coagulation and pre a izing o! the zein in solution; the ordinary claricipitation of denatured rain and other insoluble fication method having been carried out in 1 or colloidal protein bodies in the solution, and j a norance oi the fact discovered by applicant, and the solution isthen treated by filtration orsetwhich is the basis of the present invention, that tling for the removal oi-such precipitated matter. there are other bodies of an insoluble or colloidal The temperature to which "the solution is character besides the residual gluten meal which cooled should, for most eilective operation of the. iiallowedto remain in the solution, denature the process, be as low as possible without bringing taining these denatured zein or other protein uid phases.

bodies will set up to a gel quite rapidly; the time In treating zein produced by the isopropyl alrequired being dependent on the strength and cohol method reierred'to above, the extracts apnature 0! the alcohol, or other solvent of the pear to separate into two phases at 10 C. F.)

the temperature, the hydrogen ion concentranot be carried, for an extract oi-this character, tlon and upon mechanical factors promoting the quite down to 10' c. A workable temperature is denaturing operation, such agitation. But um 15' C. (59' F.) or slightly lower. Increased stader y set'oi conditions the time'within whichbility of the solution is obtained by cooling to siderably. increased by the substantially complete temperature is distinctlylesfs stable than a solo-- removal from the solution or the insoluble protion cooled to 15"-10 0. a

tein bodies which'it contains, in accordance with No definite temperature range can be given the principles of the present invention. p applicable to all solutions as the point oi s ps- A practical method of aeinirom e ration 'oi the solution intotwo liquid phases will depend to some extent upon the zein concentration, the concentration of the alcohol, or the solvent, the kind of solvent used and other factors. To obtain the best results, in respect to stability, the rule is to cool to the lowest possible temperature without bringing about the separation of the solution into two liquid phases, that is, without bringing about the stratification of the solution.

Preferably the stabilizing treatment precedes oil and color removal.

A suitable apparatus for practicing the process is illustrated, diagrammatically, in the accompanying drawing.

This apparatus consists of two cooling units through which the extract passes successively. A single unit might be used. The two unit system is preferable because part of the cooling may be done with water as a cooling agent, thus reducing the amount of artificial refrigeration required.

Referring to the drawing, I designates a cooling unit towhich the hot extract from the extracting apparatus is delivered through pipe: 2. The vessel is provided with a water cooled reflux condenser 3 and subjected to a vacuum of 27 inches of mercury, ,the pipe leading to the vacuum pump (notshown) being designated 4. The solution in vessel I is reduced to a temperature of about 30 C. (86 F.) and then passes through pipe 5 to a second cooling vessel 6 provided with an ammonia cooled reflux condenser I in which the pressure is reduced to a 29 inch vacuum, the pipe leading to the vacuum pump (not shown) being designated 8. The solution in vessel 2 being reduced to a temperature of about 15 C. (59

F.), or slightly lower, passes through pipe 9 to a filter Ill or other apparatus for separating the coagulated and precipitated impurities from the solution, which latter go through pipe II to The intention is to cover by patent all equiv alents and all modifications of process and apparatus within the scope of the appended claims.

This application is a continuation in part of applicants pending application Serial 155,691, filed July 26, 1937, for Stabilization of zein by clarification.

I claim:

1. Treatment of an alcoholic zein solution to stabilize it which comprises: cooling the solution to a temperature above that at which the solution separates into two liquid phases whereby protein bodies are precipitated which, if allowed to remain in the solution, denaturize soluble zein; and removing such bodies from the solution.

2. Treatment of an alcoholic zein solution to stabilize it which comprises: cooling the solution to a temperature between 20 and 10 C. (68 and 40 F.) to precipitate protein bodies which, if allowed to remain in the solution, denaturize soluble zein; and removing such bodies from the solution.

'3. Treatmentjof an alcoholic zein solution to stabilize it which comprises: cooling the solution to a temperature of about 15 C. (59 F.) to

precipitate protein bodies which, if allowed to remain in the solution, denaturize soluble zein; and removing such bodies from the solution.

4. Treatment of an alcoholic zein solution to stabilize it which comprises: cooling the solution under vacuum to a temperature above that at which the solution separates into two liquid phases whereby protein bodies are precipitated which, if allowed to remain in the solution, denaturize the soluble zein; and removing such bodies from the solution.

5. Treatment of an alcoholic zein solution to stabilize it which comprises: cooling the solution under vacuum at two stages in the latter of which the vacuum is increased, to a temperature above that at which the solution separates into two liquid phases whereby protein bodies are precipitated which, if allowed to remain in the solution, denaturize soluble zein; and removing such bodies from the solution.

6. In the production of zein: extracting the zein from corn gluten with an alcoholic solvent and heat; cooling the extract to a temperature which is above that at which the solution separates into two liquid phases; and removing precipitated protein bodies whereby the stability of the solution is increased.

7. In the production of zein: extracting the zein from corn gluten with an alcoholic solvent and the application of heat; cooling the extract to a temperature between 20 C. and 10 C. (68 and 40 F); and removing precipitated protein bodies whereby the stabilityof the solution is increased.

8. In the production of zein: extracting the zein from corn gluten with an. alcoholic solvent and the application of heat; cooling the extract in vacuo to a temperature above that at which the solution separates into two liquid phases; and removing precipitated protein bodies from the solution, whereby the stability of the solution is increased.

9. In the production of zein: extracting the 'zein from corn gluten with an alcoholic solvent and the application of heat; cooling the extract in vacuo to reduce it to a temperature between 20 and 10 C. (68 and 40 F.) and removing precipitated protein bodies from the solution whereby the stability of the solution is increased.

LLOYD C. SWALLEN. 

